作者:J. Kleinschroth、J. Hartenstein
DOI:10.1055/s-1988-27770
日期:——
Reaction of 2,5-dimethoxybenzaldehyde with tosylmethyl isocyanide in tetrahydrofuran in the presence of potassium tert-butoxide affords N-[2-(2,5-dimethoxyphenyl)-1-tosylethenyl]formamide with assumed E-stereochemistry. Reductive detosylation of this compound with sodium borohydride in dimethylformamide and O-demethylation of the resultant (Z)- N-[2-(2,5-dimethoxyphenyl)ethenyl]formamide with boron tribromide in dichloromethane yields cis-erbstatin whereas equilibration of (Z)- N-[2-(2,5-dimethoxyphenyl)ethenyl]formamide by irradiation in toluene in the presence of iodine, isolation of the E-isomer from the Z/E mixture thus formed, and O-demethylation with boron tribromide in dichloromethane yields (trans-)erbstatin.
在叔丁醇钾存在下,2,5-二甲氧基苯甲醛与甲苯基甲基异氰酸酯在四氢呋喃中发生反应,生成具有假定 E-立体化学结构的 N-[2-(2,5-二甲氧基苯基)-1-甲苯基乙烯基]甲酰胺。用硼氢化钠在二甲基甲酰胺中对该化合物进行还原脱甲基化,再用三溴化硼在二氯甲烷中对生成的 (Z)- N-[2-(2,5-二甲氧基苯基)乙烯基]甲酰胺进行 O-脱甲基化,得到顺式阿司他丁,而将 (Z)- N-[2-(2,5-二甲氧基苯基)乙烯基]甲酰胺在二氯甲烷中平衡,则得到顺式阿司他丁、(Z)-N-[2-(2, 5-二甲氧基苯基)乙烯基]甲酰胺在碘存在下在甲苯中进行辐照平衡,从由此形成的 Z/E 混合物中分离出 E 异构体,然后在二氯甲烷中用三溴化硼进行 O-脱甲基反应,得到 (反式)厄铂。